A stapler is a medical device instead of a conventional manual suture in surgery. A tubular stapler is widely applied in human digestive tract surgery, for example, end-to-end or end-to-side anastomosis for the esophagus, stomach, duodenum, small intestine, etc. in a digestive tract. Especially in the case of relatively short operated connecting portion or unclear line of sight, a stapler needs to be used to achieve wound suturing. In surgery such as digestive tract reconstruction, a medical stapler is used to assist incision suturing, which has advantages of being simple in operation and rapid in suturing and substantially having no side effects and complications.
It is well known that a high-quality anastomosis technique is the key to determining whether a surgery is successful, while the success of the anastomosis technique is closely related to the structure of the used stapler. The security, usability and stability of an anastomosis device having a decisive influence on the success of the anastomosis technique are the key to successfully carrying out this type of surgery.
The medical stapler generally comprises an anvil assembly, a cartridge assembly, a connecting assembly, a firing assembly, a transmission assembly, a pivoting handle, a stationary handle and an adjusting assembly. Various improved medical disposable stapler are also known in the prior art. For example, Chinese invention patent 200710107833.8 discloses a disposable stapler having an automatic safety means. In this stapler, a pivoting handle located in the rear of the stapler is an automatic safety handle mounted on a stationary handle via an axle pin, and the axle pin is connected to a reset spring. By adopting such a disposition, the problem in unsuitably sending out a staple due to the fact that a doctor inadvertently touches the handle in operation may be solved. The entire contents of the above invention patent are incorporated herein by reference. For example, Chinese utility model patent 200820178201.0 discloses a disposable stapler having vent holes. The anvil at the head of the stapler is formed with one to three vent holes, thus eliminating the overhigh pressure in the anastomotic stoma, avoiding the impact on the stapling effect caused by the fact that the anastomotic stoma breaks, and avoiding the adverse impact on the postoperative tissue recovery of a human body. The entire contents of the above utility model patent are incorporated herein by reference.
After surgery, the entire stapler together with the anvil needs to be drawn out. In the case of minimally invasive surgery, the diameter of the anastomotic stoma is relatively small, so that staples of the stapler may easily fall off and the anastomotic stoma may break when the conventional stapler is taken out. To this end, Chinese invention patent application 201010112511.4 and Chinese utility model patent application 201020122097.0 of the applicant proposed a stapler having a tiltable anvil. After the anastomosis operation, the anvil can be tilted, and consequently the anvil may easily pass through smaller anastomotic stoma, thus reducing the risk of postoperative complications. The entire contents of the above invention patent application and the above utility model patent application are incorporated herein by reference.
However, in the traditional stapling surgery, the stapler is placed in a human tissue when a cap-shaped anvil is in a vertical state. This surgery has the following disadvantages. As the profile area of the stapler is large when the stapler is placed in the human tissue, it is difficult to place the anvil in the human tissue. Moreover, mucosal tissues in the lumen of the human tissue may be easily pushed in, but are not impaled when forming a purse and stapling, thus making it possible to bring various postoperative complications.
In order to overcome the above shortcomings in the prior art, there is a need for a stapler which has a small profile area when placed in and taken out of a human tissue and has a simple structure and a safe and convenient operation, so that the stapler may be easily placed in the human tissue and the anvil may easily pass through a small anastomotic stoma after the anastomosis. Therefore, the risk of postoperative complications may be reduced.